This invention related to an inverter of the kind for driving a motor or the like.
Japanese Patent Publication 9-70177, for example, disclosed an inverter adapted to detect its output current and to stop its operation if an excessively strong current likely to damage the inverter or the motor is detected, interpreting that an abnormal condition has occurred. If the motor and/or any of the components of a system being driven by the motor has become worn and has reached a point where it is required to be replaced, however, such a prior art inverter is not adapted to detect such a situation. Thus, the motor and/or a system component may be damaged, thereby forcing the user to stop the system operation.